1. Field of the Invention
The present invention relates generally to a semiconductor structure and process thereof, and more specifically to a semiconductor structure applying isolation slots in metal gate strips and process thereof.
2. Description of the Prior Art
Poly-silicon is conventionally used as a gate electrode in semiconductor devices, such as the metal-oxide-semiconductor (MOS). With the trend towards scaling down the size of semiconductor devices, however, conventional poly-silicon gates face problems such as inferior performance due to boron penetration and unavoidable depletion effect. This increases equivalent thickness of the gate dielectric layer, reduces gate capacitance, and worsens a driving force of the devices. Therefore, work function metals that are suitable for use as the high-K gate dielectric layer are used to replace the conventional poly-silicon gate to be the control electrode.
As work function metals replace conventional poly-silicon gates, relating semiconductor processes also need to be adjusted to form semiconductor components having improved performance.